Cardiac necropsy findings are described in a 72-year-old man with Tangier disease whose plasma total cholesterol levels averaged 70 mg/dl, low- density lipoprotein cholesterol 45 mg/dl, and high-density lipoprotein cholesterol 1.4 mg/dl, and who had coronary artery bypass grafting for severe atherosclerotic coronary artery disease. At necropsy, 24 (33%) of the 72 five-mm segments of the 4 major (right, left main, left anterior descending and left circumflex) native coronary arteries and 4 (15%) of the 27 five-mm segments of the saphenous vein aorto-coronary bypass conduits were narrowed greater than 75% in cross-sectional area by atherosclerotic plaques. The plaques were composed primarily (91-97%) of fibrous tissue. Oil red O staining, polarized light microscopy, and electron microscopy showed the presence of cholesterol deposits in the plaques and in the walls of coronary arteries, saphenous vein grafts and aorta. Such deposits also were found in foam cells of histiocytic origin, fibroblasts in all 4 cardiac valves and in Schwann cells of cardiac nerves.